Knitting machines having linearly arranged needles

ABSTRACT

In a knitting machine having at least one set of linearly arranged needles and motor operated means for moving the selvedge stop and/or fashioning points of said machine during the production of a series of garment blanks, the provision of at least one coded element associated with said needles, reading means adapted to scan said coded element and to transmit a signal to a comparator indicating the actual position of said stop and/or points, at least one coded tape, other reading means adapted to scan said tape and to transmit a signal to said comparator indicating a position to which said stop and/or said points are to be moved, and means which utilize said information imparted to said comparator to control the speed, and the direction of operation, of said motor operated means. Means are also provided to limit the extent of movement imparted by said motor controlled means to said stop/or points.

Ladyman et al.

[ KNITTING MACHINES HAVING LINEARLY ARRANGED NEEDLES [75] Inventors:Peter Francis Ladyman, Long Eaton; Dennis Gaunt, Berry Hill, both ofEngland [73] Assignee: Stibbe-Monk Developments Limited, Leicester,England [22] Filed: Apr. 13, 1972 [21] App]. No.: 243,591

[30] Foreign Application Priority Data Apr. 23, 1972 Great Britain 1111272 [52] US. Cl. 66/89 [51] Int. Cl D04b 11/06 [58] Field of Search66/89, 176, 67, 90, 66/91, 126, 154 A [56] References Cited UNITEDSTATES PATENTS 3,262,286 7/1966 Bentley et al 66/89 3,019,626 2/1962Blood....... 3,624,707 ll/l97l Scheller 66/96 1 Jan. 8, 1974 3,589,1456/197! Koblitz ..66/89 mar .Eaemi zwllonald.fel baurit.,i

Attorney-Bladwin, Wright & Brown [5 7] ABSTRACT nal to said comparatorindicating a position to which said stop and/or said points are to bemoved, and

means which utilize said information imparted to said comparator tocontrol the speed, and-the direction of operation, of said motoroperated means. Means are also provided to limit the extent of movementimparted by said motor controlled means to said stop/orpoints.

9 Claims, 6 Drawing Figures PATENTED JAN 81974 SHEET 1 OF 5 PATENTED JAN81974 SHEET 3 BF 5 PMENTEU JAN 974 SHEET 5 BF 5 This invention relatesto knitting machines having linearly arranged needles and isparticularly concerned with the control of the lengthwise movement ofthe nut housings along screws, commonly referred to as fashioningscrews, of such machines. As is usual, the latter mechanism, in additionto controlling fashioning, also controls the loop transfer elements forpatterning, and also the knitting width when no fashioning is takingplace.

More specifically, this invention relates to multi-head knittingmachines in which each head is provided with one or more sets oflinearly arranged knitting needles, and one or more control bays areprovided to control the operation of said multiple of knitting heads.Such machines are well known in the art and are more speciflcallyreferred to as multi-head flat, vee bed and straight bar knittingmachines.

It is known in such knitting machines to have at least one pair offashioning screws, one for controlling the left hand, and the other forcontrolling the right hand, selvedge of a garment blank. The fashioningnuts are moved in either direction to reset the knitting width stopsand/or position the fashioning points. Such movement is obtained byracking mechanisms attached to each screw, which mechanisms arecontrolled from chains, cams, punched control tapes or the like. Onesuch arrangement is shown in our prior British Pat. No. 1,088,712.

It is further known, particularly on straight bar machines, to haveanother set of fashioningnuts, or coupling and uncoupling mechanisms,separate from the existing fashioning nuts so that lacing and V-neckloop transfer operations can be carried out by separate sets of transferpoints.

THe racking mechanisms and associated controls generally employed forturning the fashioning screws are very bulky mechanical arrangement and,from the point of view of moving the nuts the equivalent of more thantwo or three needle pitches, are slow moving and therefore take upvaluable knitting time. In fact, such mechanisms generally are only ableto rack in either direction the equivalent of one or two needle pitchesper rack. Y

It is also known on straight bar machines for the purpose of moving thefashioning nuts long distances, such as when resetting the knittingwidth at the start of a new garment blank, to couple the fashioningscrews to a motor drive in order to save time. The positions to whichthe fashioning nuts are moved in this case are controlled by a number ofmanually preset switches which are rendered effective, in predeterminedorder, under the control of a punched tape. The rotation of thefashioning screws is finally controlled by a plunger dropping into anotch associated with the screw and this accurately aligns the transferpoints and draw mechanisms with a needle. In this case, the normalracking mechanisms are retained for fashioning and lacing, etc.

It is the main object of the present invention to provide means whichenable the fashioning screw housings, and their associated parts, suchas draw stops for width control and fashioning points, to be moved alengthwise distance equivalent to any number of needle pitches, by usinga driving motor controlled from binary coded strips and photo-sensingmeans common to all stop positions.

It is a further object-of the present invention to obviate the necessityfor the bulky and expensive racking mechanisms at present associatedwith all such fashioning screws by using an accurately controlleddriving motor.

According to the present invention, there is provided a knitting machinehaving one or more sets of linearly arranged needles and motorcontrolled means for linearly moving a machine part, such as a selvedgestop and/or fashioning points, from one position to another during theproduction of a series of garment blanks, which comprises reading meansadapted to scan at least one coded element associated with the needlesof the machine and to transmit a signal indicating the actual positionof said machine part to a comparator, at least one coded control tapeadapted to transmit a signal to the comparator indicating a position towhich said machine part is to be moved, and means adapted to utilize theinformation imparted by the comparator to control the speed, and thedirection of operation, of said drive motor.

Morespecifically, the control means consists of two binary codedlongitudinally extending plates arranged in a control bay of themachine. The plates are associated with the fashioning screws, one'withthe left hand (Ll-l.) fashioning screw(s) the other with the right hand(R.l-l.) fashioning screw(s). The plate associated with the L.H. screwhas punched therein a code for each needle position in the left handhalf of the needle beds, and the plate associated with the RH. screw haspunched therein a code for each needle position in the right hand halfof the needle beds. A stationary reading head scans its correspondingplate, each of which plates is movable with one of the fashioning nuts,

in order to relay back to a comparator the exact position at which thefashioning nut, and its associated stops, are at any onetime. By usingtwo such arrangements, one for controlling the LB. selvedge and one forcontrolling the RH. selvedge, it is possible to knit garmentsassymetrically of the knitting heads of the machine. i

ator. This control tape is punched with the code of the needle positionto which it is required to move the respective fashioning nuts. Thisinformation is analysed by a controller associated with the comparatorand control signals are passed to the respective motor drive units forthem to rotate the screw or screws at a fast speed for a certaindistance of travel of the respective nuts. This distance is in apositive or negative direction up to within about five needle pitches ofthe required positions. For movement within the latter distance, a slowtravelling speed is selected for driving the screws. For the purposes offinal alignment and accurately stopping the fashioning nuts at apredetermined needle position, it may be advantageous to provide asimplified racking arrangement, of a notched ring and plungerarrangement, associated witheach fashioning screw.

The invention will now be described, by way of example, with referenceto the accompanying drawings in which,

FIG. 1 is a front view of so much of a control bay of the machine as isnecessary to describe the invention,

FIG. 2 is a part section, on an enlarged scale, on the line IIII of FIG.1,

FIG. 3 is a more general, part plan view of the mechanism with certainparts omitted for clarity,

FIG. 4 is a front view corresponding to FIG. 3,

FIG. 5 is an end view in the direction of the arrow VI of FIG. 4, and

FIG. 6 is an electrical circuit block diagram.

Referring to the drawings, there is shown part of a central control bayfor a multi-head flat or V-bed knitting machine having front and rearco-acting needle beds. On each side of, and controlled from, the controlbay, are three knitting heads each of which is adapted to produce fullyfashioned rib and/or plain fabric garment blanks simultaneously with theother knitting heads of the machine. It is to be noted that, for thepurposes of this description, generally only the left hand (LI-I.)selvedge mechanism is shown and described in detail, but there is ofcourse a right hand (R.I-I.) selvedge mechanism which is a mirror imageof the L.I-I. mechanism. However, where corresponding parts of the RH.mechanism are shown, these are indicated by a tick after the referencenumeral.

Thus, the L.H. selvedge mechanism comprises a fashioning screw 1controlling the selvedge position in respect of the front needle bed anda fashioning screw la in respect of the selvedge position of the rearneedle bed. The screws 1 and 1a are controlled by means common to themboth as hereinafter described.

The screws 1 and 1a are supported for rotation in bearings housed insupports 2 and 3 forming part of the framework of the machine, otherparts of the framework being generally indicated by the reference F.Each of the fashioning screws has mounted thereon a nut housing 4. TheL.I-I. nut housings 4 are coupled, either directly or indirectly, toknitting width control stops on the left hand side of each knitting bayand/or to left hand fashioning controls. The form of the knitting widthand fashioning controls may be of any known type examples of which aredisclosed in our prior British Pat. specification No. 1,088,712 and ourco-pending British Pat. specification No. 1,272,309.

The nut housing 4 of fashioning screw 1 is additionally connected to anactuating bar 5 having, at one end thereof, a transversely disposedchannel-shaped bracket 6. The connection between the housing 4 and thebar 5 consists of a bracket 7 supporting a rod 8 the free end of whichis positioned in the bracket 6 and is secured to the bracket 6 by meansof adjusting screws 9 so that the endwise position of the bar 5 can beaccurately located. The actuating bar 5 is mounted in a guide channel 10secured to a frame member F and is slidable in bearing races 11.

Attached to the bar 5, as by screws 12, is a control plate 13 which isprovided along its length with a binary code for each needle position'ofthe left hand half of the needle bed. The code is in the form of holesand no hole markings. Centrally located within the control bay is ascanning head assembly which provides a scanning head and a light sourcefor each of the left and right hand control plates 13 and 13'. Thecontrol plate 13' for the right hand half of each needle bed is mountedabove and to the right of the left hand control plate 13 and in asimilar manner to the latter.

The scanning head assembly is shown in section in FIG. 2 and consists ofthe two reading heads 14 and 14' attached to a plate 15, and two lightsource units 16 and 16' attached to a plate 17. The plates 15 and 17 areboth fixedly held in a bracket 18 which is attached to a plate 19 on thesupport 2. The control plate 13 can pass freely between the reading head14 and the light source 16 and the control plate 13' can pass freelybetween the reading head 14' and the light source 16'. In FIG. 1, thefashioning nut housing 4 of screw 1 and associated parts, together withcontrol plate 13, as shown in their outermost positions so that, in thisposition, the code which is transmitted by the reading head 14 relatesto the outermost left hand needle position. As the fashioning nuthousing 4 is moved to its right in FIG. 1, the codes for successivelyinward related needle positions are scanned and transmitted.

To move the fashioning nut housings 4, the fashioning screws 1 and 1aare rotated by reversible drive means of the electrical or hydraulictype either directly or, more likely, through gearing or chainarrangements. The direction and number of rotations imparted to thescrews 1 and la is dictated from a controller under instruction of acontrol tape and associated reading head compared by a comparator toreadings from the control plate 13.

In order to turn the fashioning screws 1 and la, and to accuratelyposition the nut housings 4 lengthwise of the screws, the screws havemounted on their outer ends helical gears 20 in mesh respectively withhelical gears 21 fixed to the ends of a driven shaft 22. A driven pulley23 is arranged centrally on the shaft 22 and is driven, via a belt 24,by a drive pulley 25 mounted on the output shaft 26 of an hydraulicallyoperated motor and clutch unit 27. Suitable idler pulleys 28 areprovided to tension the drive belt 24. The motor 27 is controlled by asolenoid operated control valve 29 which controls the oil flow from amain hydraulic pump and motor 30.

Also attached to the outer end of each of the screws 1 and 1a is a cam31 having four notches 32 which represent, in one revolution, foursuccessive needle positions. A plunger device 33 is positioned to enterinto engagement with one of the notches 32 dependant upon the needleposition required. The plungers 33 are attached to bellcrank levers 34which are interconnected by a link 35, the plungers 33 being moved outof an operative position where they engage their coacting notches 32 bymeans of a singleacting hydraulic jack 36 coupled to one of the levers34. Movement of the plungers 33 into an operative position is effected,when the pressure on jack 36 is released, under the action of a tensionspring 37 extending between the other lever 34 and a frame member F, thespring 37 also serving to impart resiliency to the plungers 33 as theyare moved into engagement with the notches. The jack 36 is also underthe control of the control valve 29.

Associated with one of the pair of earns 31 and coacting plungers 32 aretwo proximity switches 38 and 39 (FIGS. 5 and 6) of the Gigatronic G.A.Type made by Kubler Impulsgeratebau. These switches are of the typewhich detect the proximity of metal to their end faces and only then dothey allow electric power flow ing into them to pass out again therebycreating an output signal which is relayed to a main logic unit 40 (FIG.6) which controls the operation of the control valve 29. Thus, theswitch 38 relays a signal each time it is safe to allow the plungers 33to be dropped into the notches 32, it being understood that normally theplungers are riding on the faces of the cams so that they automaticallydrop into the next succeeding notches as the cams are rotated. Theswitch 39 serves to relay a signal only when the plungers 33 havedropped into the notches 32 whereby a signal is passed to the controlvalve 29 to stop operation of the motor 27.

A further switch 41 (FIG. 5), in the form of a microswitch, isassociated with one of the plungers 33 and is arranged to close onlywhen the plunger 33 has dropped into a notch 32. This switch passes asignal to the unit 40 and indicates that a fashioning operation iscomplete so that the knitting cam can re-commence operation.

Two further switches 42 and 43, in the form of limit switches areprovided to co-act with the fashioning screw nut housing 4. Theseswitches are operated only if the nut housing 4 travels beyond its safedistance in either direction thereby providing a safety feature if thewrong information is fed into the unit 40, say by the control tape.

With the arrangement just described, it is possible to do without thebulky and complicated racking mechanism, an example of which is shown inBritish Pat. No. 1,088,712, even for the narrowing and wideningcontrols, for fashioning, lace and pattern work, etc.

One of the advantages of the present invention resides in the time savedwhen resetting the knitting width controls for differently contouredgarment blanks to be knitted in succession, i.e., so-called sequentialknitting.

The electrical arrangement for controlling these functions will now bedescribed with reference to FIG. 6. Timing is controlled by pulsesemitted from a clock 44 to a time co-ordina'tor 45 for distributing thebinary coded decimal numbers at the correct time.

A programme tape with punched binary coded information .is read by atape reader 46 which transmits the information regarding which needleposition the fashioning nut housing-4 is to next move to. An alternativeform of control, called a manual set control-47, can be used andconsists of manually selectable dial switches which are set up for theappropriate needle position next required. This information is thenpassed to a decima] to binary converter 48 which passes the information,in binary form, to a data selection unit 49. The data selection unit 49is instructed which information, manual or tape, to pass on further bymeans of a manual or tape selection switch 50.

The position, in binary coded form, to which the fashioning nut housing4 is to move to is now transmitted to a store 51 and this informationwill hereinafter be referred to, for the sake of simplicity, asinformation B. The information B is passed onto an adding unit 52, thepurpose of which will become clear hereinafter.

Meanwhile, the light sensor 14 of the reading head, indicated generallyin FIG. 6 by numeral 53, transmits the-binary coded informationregarding the actual position of the fashioning nut housing 4 to a store54. This information for the sake of simplicity, will hereinafter bereferred to as information A. Timing and control signals are transmittedto both stores 51 and 54 from the time co-ordinators 45.

Information A and B is then passed to comparator 55 which transmitsinformation as to whether A is greater than, equal to, or less than, Bto the speed and direction logic unit 40 and a selection unit 56. Thisinformation is utilised by the direction logic unit 40 to initiate traversing movement of the nut housings either in a positive or negativedirection, or no movement at all.

With the respect of information transmitted to the selection unit 56, itis to be understood that for distances of over five needle pitches afast speed traverse is engaged, and for distances of five and lessneedle pitches a slow speed traverse is engaged, and that between thedistance of one needle pitch and none, the plungers 33 of FIGS. 4 and 5are released to drop into the first notches 32 they encounter. Thecomparison of information A and B is transmitted to the selection unit56 which stores the selected pre-strapped numbers i.e. the number of theneedle position at which a speed change is to take place as describedabove. Synchronising pulses are also transmitted to the selection unit56 from the time co-ordinator 45, which also transmits pulse signals tostores 57 and 58 and to the direction logic unit 40. v

The information from unit 56 is now passed to the adding unit 52 whichadds or subtracts as the case may be the pre-strapped numbers, i.e., i 5and i- 1. These figures are then passed to the stores 57 and 58 whichrespectively store the information B i 5 and information B i 1. Thisinformation, together with information from store 54 is passed to, andcompared in, compara tors 59 and 60. The comparator 59 comparesinformation A relative to information B i 1. The resultant informationis passed to the speed and direction logic unit 40 which now has thenecessary information for moving, via the control valve 29 abd motor 27,the fashioning nut housing 4 at the required speed, and in the requireddirection.

For the purpose of effecting a fashioning operation reference is alsomade to FIG. 6.

Firstly, the control tape does not give an instruction to move the nuthousings 4 to aparticular needle position, but gives an instruction tomake a number of fashionings (narrowing or widening) every so manycourses of so many wales each,i.e., 10 narrowing movements every 4courses by 4 wales pitch.

This information is passed from the'reading head 46 to a calculator unit61 which also receives a signal from the store 54 informing it of theposition of the fashioning nut housing 4. The calculator6l then informsthe data selection unit 49 which position the fashioning nut is to moveto have added thereto or substracted therefrom the appropriate number ofwales. This will continue until all the fashionings have been completed,the electrical control working from the data selection unit 49 in themanner hereinbefore described for rack reset control.

There is also a fashion limit unit 62 which is preset with a maximumnumber of wales over which any one fashioning operation can take place.When a fashioning operation is to be carried out, an informing signal issent to the fashion limit comparator 62 from the reading head 46. Thefashion limit comparator 62 will then inhibit any instructed movement bythe data selection unit over a certain amount, probably 4 wales.

There is also a limit comparator 63 which receives a signal from store51' related to the position to which the fashioning nut housing 4 is tobe moved. Stored in comparator 63 are the maximum and minimum positionallimits to which the fashioning nut 4 can safely be moved and if theinformation received by limit comparator 63 is outside these limits, astop signal is transmitted to the speed and direction logic unit 40.

In operation therefore, the main control tape (not shown) scanned byreading head 46 for the purpose of carrying out this invention containsinformation relative to fashioning and/or garment reset. in the case offashioning, the information required is the number of fashionings, theirfrequency and walewise movement. In the case of garment reset it is thecode of the needle at which the next garment width is to start. Thisinformation, as previously described, is fed in appropriate form tocomparators, from which appropriate signals are transmitted to the speedand direction logic unit 40 which will operate the solenoid valve 29according to the direction, duration and speed of traverse required.

The direction of traverse is governed by the solenoid valve 29 whichincludes a two-way valve which allows oil to flow in one direction whenin one extreme position, and in the other direction when in the otherextreme position, and stops oil flow when in a central position.

Although the earns 31 are shown and described as having four notches 32,this is not limititive in that it may vary according to the gauge of theneedles and/or to the pitch of the fashioning screws. Thus, for example,a cam with seven notches would be suitable for both 14 and seven gaugemachines provided the thread pitch of the fashioning screws is twice aswide on the seven gauge machine as it is on the 14 gauge machine.

Furthermore, although the invention has been described with reference toflat or v-bed knitting machines having two co-acting needle beds, itwill be understood that it can equally well be applied. to straight barknitting machines having one or two needle beds.

Although the invention has been described with reference to controllingthe positions of the nut housing on the fashioning screws of-a knittingmachine, it will be understood that it is not limited in this respect.Thus, the control may be applied to other similar functions of knittingmachines.

We claim:

1. A multi-head knitting maching having a control bay, a plurality ofknitting heads each having at least one set of linearly arrangedknitting needles, at least one fashioning screw arranged in said controlbay, a fashioning nut means including a nut housing mounted on eachfashioning screw, machine parts means of the type including selvedgestops and fashioning points attached to said nut housing for co-actingwith said sets of knitting needles, and motor operated means connectedto said fashioning screw for imparting rotation to said fashioning screwfor causing lengthwise movement of said fashioning nut housings, atleast one coded element attached to'said nut housing and operativelyassociated with said needles of the machine, a comparator, reading meanscoupled to said comparator for scanning said coded element andtransmitting to said comparator a signal indicating the actual positionof said fashioning nut housing, at least one coded control tape, otherreading means coupled to said comparator for scanning said coded controltape and transmitting to said comparator a signal indicating a positionto which said fashioning nut housing is to be moved, and means coupledto said motor operated means for utilizing information imparted theretoby said comparator to control the speed and the direction of operationof said motor operated means, said coded element comprising a controlplate formed with coded information, an actuating bar supporting saidcontrol plate and adjustably connected to said nut housing, said controlplate being movable under the action of said nut housing relative toreading means, said reading means being disposed in said control bay.

2. Aknitting machine according to claim 1, in which said reading meanscomprises a reading head mounted in spaced relationship with a lightsource with said control plate being positioned between said readinghead and said light source.

3. A multi-head knitting machine having a control bay, a plurality ofknitting heads each having at least one set of linearly arrangedknitting needles, left hand and right hand fashioning screws arranged insaid control bay, a fashioning nut housing mounted on each of saidfashioning screws, machine parts attached to said nut housings forco-acting with said sets of knitting needies, and motor operated meansconnected to said fashioning screws for imparting rotation to saidfashioning screws and cause lengthwise movement of said fashioning nuthousings; at least one coded control plate attached to each of said nuthousings and operatively associated with said needles of the machine, adigital comparator, a scanning head assembly connected to saidcomparator and having a reading head and a light source positioned toscan said coded control plates and being operative to transmit to saidcomparator a signal indicating the actual position of said fashioningnut housings, at least one coded control tape, reading means connectedto said comparator for scanning said coded control tape and transmittingto said comparator a signal indicating positions to which saidfashioning nut housings are to be moved, and means connected to saidcomparator for receiving information-and utilizing v such information tocontrol the speed and the direction of operation of said motor operatedmeans; said motor operated means including an hydraulic motor, asolenoid operated control valve controlling said motor, and drive meansconnecting said motor and said fashioning screws.

4. A knitting machine according to claim 3, including means foraccurately limiting the extent of rotation of said fashioning screws,said screw rotation limiting means comprising a notched cam mounted oneach of said fashioning screws and a plunger deviceassociated with eachcam for engagement in said notches thereof.

5. A knitting machine according to claim 4, in which each of saidplunger devices is biased by spring means into an operative positionwhere it engages one of said cam notches.

6. A knitting machine according to claim 5, including hydraulic jackmeans for moving said plunger devices into an inoperative position freeof said notches.-

7. A knitting machine according to claim 6, including switch means forindicating when said plungers can be moved into an operative position.

8. A knitting machine according to claim 7, including other switch meansfor indicating when said plungers of an operation.

1. A multi-head knitting maching having a control bay, a plurality ofknitting heads each having at least one set of linearly arrangedknitting needles, at least one fashioning screw arranged in said controlbay, a fashioning nut means including a nut housing mounted on eachfashioning screw, machine parts means of the type including selvedgestops and fashioning points attached to said nut housing for co-actingwith said sets of knitting needles, and motor operated means connectedto said fashioning screw for imparting rotation to said fashioning screwfor causing lengthwise movement of said fashioning nut housings, atleast one coded element attached to said nut housing and operativelyassociated with said needles of the machine, a comparator, reading meanscoupled to said comparator for scanning said coded element andtransmitting to said comparator a signal indicating the actual positionof said fashioning nut housing, at least one coded control tape, otherreading means coupled to said comparator for scanning said coded controltape and transmitting to said comparator a signal indicating a positionto which said fashioning nut housing is to be moved, and means coupledto said motor operated means for utilizing information imparted theretoby said comparator to control the speed and the direction of operationof said motor operated means, said coded element comprising a controlplate formed with coded information, an actuating bar supporting saidcontrol plate and adjustably connected to said nut housing, said controlplate being movable under the action of said nut housing relative toreading means, said reading means being disposed in said control bay. 2.A knitting machine according to claim 1, in which said reading meanscomprises a reading head mounted in spaced relationship with a lightsource with said control plate being positioned between said readinghead and said light source.
 3. A multi-head knitting machine having acontrol bay, a plurality of knitting heads each having at least one setof linearly arranged knitting needles, left hand and right handfashioning screws arranged in said control bay, a fashioning nut housingmounted on each of said fashioning screws, machine parts attached tosaid nut housings for co-acting with said sets of knitting needles, andmotor operated means connected to said fashioning screws for impartingrotation to said fashioning screws and cause lengthwise movement of saidfashioning nut housings; at least one coded control plate attached toeach of said nut housings and operatively associated with said needlesof the machine, a digital comparator, a scanning head assembly connectedto said comparator and having a reading head and a light sourcepositioned to scan said coded control plates and being operative totransmit to said comparator a signal indicating the actual position ofsaid fashioning nut housings, at least one coded control tape, readingmeans connected to said comparator for scanning said coded control tapeand transmitting to said comparator a signal indicating positions towhich said fashioning nut housings are to be moved, and means connectedto said comparator for receiving information and utilizing suchinformation to control the speed and the direction of operation of saidmotor operated means; said motor operated means including an hydraulicmotor, a solenoid operated control valve controlling said motor, anddrive means connecting said motor and said fashioning screws.
 4. Aknitting machine according to claim 3, including means for accuratelylimiting the extent of rotation of said fashioning screws, said screwrotation limiting means comprising a notched cam mounted on each of saidfashioning screws and a plunger device associated with each cam Forengagement in said notches thereof.
 5. A knitting machine according toclaim 4, in which each of said plunger devices is biased by spring meansinto an operative position where it engages one of said cam notches. 6.A knitting machine according to claim 5, including hydraulic jack meansfor moving said plunger devices into an inoperative position free ofsaid notches.
 7. A knitting machine according to claim 6, includingswitch means for indicating when said plungers can be moved into anoperative position.
 8. A knitting machine according to claim 7,including other switch means for indicating when said plungers are in anoperative position.
 9. A knitting machine according to claim 8,including further switch means operative with said other switch meansfor transmitting a signal indicating completion of an operation.